Easy Electronics

This is a basic circuit of a step up DC-DC converter which the output voltage is more than the
input, the circuit could be used to power a 9v or more devices from a 6v or even a 1.5v battery, charge batteries (3-12v) with 1.5v solar cell...

The circuit uses an oscillator using Schmitt trigger, all types of oscillators works, one transistor (Ex: BD139 or similar), resistors, coil (many different
types of coils work even a small DC motor works! or you can wind 60 turn on ferrite)

R1 and C1 determine the oscillation frequency, different types of coils perform differently at frequencies changes.
I used 5v input and toroid ferrite, the output exceed 60v (no load). The output voltage will drop as the load go higher.

Joule thief is a simple step up converter, that converts DC to DC, for example you can drive a 3.4V Led with single 1.2V battery, even if the battery is almost dead. It extract all the energy stored in batteries.

You need:

1Kohm resistor.

small NPN transistor ( for example 2N3904 ).

ferrite toroid, (can be found on power supplies, radio), and wire to wrap around the toroid, ( big toroid and more turns = more output power and voltage you get ) the method of wiring is shown under, (if you don't have the toroid try the other methods under).

and Led or anything you can't drive with one battery like: leds, lighting a neon lamp, charging capacitors with high voltage, charging other batteries Ex: charging 3.6V batteries with 1.2V battery...

you can change the 1.2V battery with 9V to get high voltage output that can drive neon lamps...

This circuit is a rectangular oscillator, that generates a square wave form, thecircuitusesNAND logic gates, using CD4011 (contain 4 nand gates), the generated signal can be used as an audio alarm (by connecting a speaker directly to the output), or amplified and used as an inverter...

Theenable inputshould be (+V) so that the circuitoscillates, if it's low, the output will remainat High (+V), Ifyou do notneed acontrolled input, you can connect the two inputs of the two gates togetherandremove the connectionbetween the first and the second gate. (like the picture)

Thismay simplifythe wiring.

Caution: the common point ofthe resistorsandthe capacitoris notgrounded.

We thoughtthat limiting the current ofrechargingthe batteriesdid the trick, but no! the electrolyteleaks fromthe end of thenegative terminal, whenthe battery leaks, it losesinthe best case50% of its capacity. moreleakagealways ends with a small explosion, so another method is needed!!!

To make sure that your batteries are full charged and not damaging them, monitor their voltage, it should not exceed 110%, for example: a battery of 1.5V, maximum charge voltage is 1.65V.

(considering regeneration 80%), a 2Ah battery needs 20h for a complete recharge, Long? not really if you're not pressed.

Notes:

Before chargingthe batteriestry toselect them: never takethat are notalkaline, leakingalready, whichare rusty, which areof a mark "cheap", that give"0.00volts" or supposed tobe"outdated"for too long. Rememberthatalkalinebatteriescan be recycled. no saline lithium or any non alkaline battery it won't work and it's dangerous.